Military policemen raise their weapons at their barracks in Yemen's northwestern city of SaadaReuters

Saudi Arabia has yet again hinted that the ground invasion in Yemen against the Houthi rebels could be carried out in the coming days after the raging border clashes.

Saudi authorities have reiterated that the grand Sunni alliance, which was set up by the Arab nations against the Houthi Shiite rebels, is boosting its military presence in the Saudi Arabia-Yemen border.

Saudi Arabia shares a 1,800km-long porous border with Yemen.

"The Saudi-led air campaign may be accompanied by an operation on the ground," said Saudi Arabia's Brigadier General Ahmed Asseri, who is playing a key role at the Yemen operations. He added that "one should not expect a sudden ground attack".

"The Houthis are moving from one place to another in search of safe havens. We will make sure that there will be no safe place the militants to hide on the land of Yemen," he added.

The movement of the forces has also been intensified in the bordering region alongside the Saudi-led military campaign, dubbed as Operation Decisive Storm, in Yemen.

The spiralling unrest in Yemen has pitched the Houthi rebels, backed by Shiite-oriented Iran, against the Sunni-dominated nations of the Arab world who support the embattled Yemeni President Abd-Rabbu Mansour Hadi.

"We are not advocating war, but we are ready for it. Operation Decisive Storm will continue to defend legitimacy in Yemen. Yemenis are capable of carrying out their responsibilities in confronting Houthis, especially in view of the fact that several military personnel and civilians have joined the legitimate forces in the country," said Saudi Arabia's Foreign Minister Prince Saud al-Faisal.

The Saudi authority reiterated that security and stability in neighbouring Yemen are paramount for the kingdom.